Dispersants

Abstract

A pigment dispersant is derived from a compound of molecular weight less than 600 which contains at least three functional groups, at least one of which is an epoxy group. Preferably the compound contains at least three epoxy groups, for example triglycidyl isocyanurate. The core radical derived from the said compound is bonded to more than one solvent-compatible organic radical of molecular weight at least 200, the average molecular weight of the solvent-compatible radicals being at least 500, and to a pigment-compatible radical containing a polar group.

We claim: 
     
       1. A compound suitable for use as a dispersant for a pigment in an organic solvent, said compound being selected from the group consisting of (a) compounds of the formula ##STR4## wherein R 1  and R 2  are solvent-compatible organic radicals of molecular weight at least 200 which are the same or different, the average molecular weight of the solvent-compatible radicals R 1  and R 2  being at least 500. Q is a divalent organic group, Q 1  is hydrogen or a monovalent organic group and Z 2  is a polar group, ##STR5## being a pigment-compatible radical, and (b) compounds of the formula ##STR6## where R 1  and R 2  are hereinabove defined and Z is a pigment-compatible radical containing a polar group. 
     
     
       2. A compound as claimed in claim 1 wherein the polar group is selected from the group consisting of amino, carboxylic acid, carboxylic acid salt with an alkali metal or amine, and nitro. 
     
     
       3. A compound according to claim 1 wherein the solvent-compatible radicals comprise polyester radicals of molecular weight 1000 to 3000. 
     
     
       4. A compound according to claim 3, wherein polyester radicals are poly(12-hydroxystearic acid) radicals. 
     
     
       5. A compound having the formula: ##STR7## where R 1  and R 2  are solvent-compatible organic radicals of molecular weight at least 200 which are the same or different, the average molecular weight of the solvent-compatible radicals R 1  and R 2  being at least 500, Q is a divalent organic group and Q' is hydrogen or a monovalent organic group. 
     
     
       6. A compound having the formula: ##STR8## where R 1  and R 2  are solvent-compatible organic radicals of molecular weight at least 200 which are the same or different, the average molecular weight of the solvent-compatible radicals R 1  and R 2  being at least 500, and Z' is an aryl or aralkyl group ring-substituted by at least one nitro group. 
     
     
       7. The compound according to claim 1 wherein said pigment-compatible radicals are amino groups which are attached to an aromatic ring. 
     
     
       8. The compound according to claim 7 wherein said pigment-compatible radical is a p-aminobenzoic acid radical and the core radical is a radical of triglycidyl isocyanurate. 
     
     
       9. The compound according to claim 1 wherein at least one of said solvent-compatible radicals comprises a polyether radical having a molecular weight of 1000 to 3000. 
     
     
       10. The compound according to claim 1 wherein said at least one solvent-compatible radical includes a poly(12-hydroxystearic acid) radical.